1 Service Controller Overview

This chapter provides an overview of the Oracle Communications Service Controller.

Before you read this chapter, you should be familiar with Service Controller concepts and architecture. See Service Controller Concepts Guide for information about concepts that are common to all products in the Service Controller product line.

About Service Controller

Service Controller is a core network element providing Service Controllering in IMS/LTE and traditional SS7 networks. Positioned between applications and session control entities, Service Controller controls service delivery for sessions executed in the network. Service Controller provides Intelligent Network (IN) applications and Session Initiation Protocol (SIP) applications, with connectivity and access to the network, and control of sessions running in the network.

Service Controller implements two major functions:

  • Protocol mediation: Service Controller mediates between protocols, supporting various SS7 protocol variants and SIP, therefore enabling service delivery to different types of networks. By using Service Controller, you can deliver SIP services to subscribers in your traditional SS7 network, and IN Service Control Point (SCP) services to subscribers in your IMS/LTE network.

  • Service Orchestration: Service Controller can invoke one or more applications, combining and delivering multiple services to sessions in the network. Service Controller supports mixed orchestration of SIP-based and IN-based applications, using an orchestration logic which defines how to route sessions through a number of applications; Service Controller invokes the applications in a particular order, according to conditions in the orchestration logic that determine which applications to invoke and in what order.

Figure 1-1 shows how Service Controller is positioned between applications and session control entities, providing applications with access to sessions in the network, mediating protocols, and orchestrating services.

Figure 1-1 Service Orchestration and Protocol Mediation Across Legacy SS7 Networks and IMS/LTE Networks

Surrounding text describes Figure 1-1 .

Service Controller Use Cases

With Service Controller you can implement various solutions:

  • Next Generation Intelligent Networks (NGIN): Delivery of combined SIP services to sessions in the legacy SS7-based network.

  • Service Capability Interaction Manager (SCIM): Delivery of combined SIP services to sessions in the IMS network.

  • Service orchestration: Delivery of combined legacy IN services with new SIP services, to sessions in the IMS/LTE network.

  • IN mediation: Delivery of legacy IN services to sessions in the legacy SS7-based network, where the services and network use a different protocol variant. In this solution Service Controller converts between the two protocol variants.

For more information on the various solutions and how to implement them using Service Controller, see the solution specific chapters in this book.

The Service Controller Functional Architecture

The Service Controller signaling tier composes only Signaling Server Units (SSUs). The Service Controller processing tier includes interworking modules, supplementary modules and the Orchestration Engine, as shown in Figure 1-2.

Figure 1-2 Service Controller Functional Components in the Processing Tier

Surrounding text describes Figure 1-2 .

Inside Service Controller, communication between the Orchestration Engine and modules is normalized, based on the Session Abstraction Layer (SAL) protocol. Each module provides the conversion between the Service Controller internal SAL representation of the session and the applicable external protocol.

Orchestration Engine

The Orchestration Engine (OE) resides at the center of the Service Controller architecture and implements the service orchestration functionality. Sessions arriving through interworking modules invoke the Orchestration Engine which routes the sessions through one or more applications, based on an orchestration logic that the Orchestration Engine obtains for each session from the subscriber profile store (LSS or HSS). The Orchestration Engine invokes applications in a specific order, according to conditions that determine which application to invoke and in which order. See Service Controller Orchestration User's Guide for more information about application orchestration.

Interworking Modules

Interworking modules, often referred to as modules, provide the Orchestration Engine with communication to applications and session control entities in the SS7-based and IMS/LTE networks. Interworking modules implement the protocol mediation function; they convert messages of the relevant protocol to internal Service Controller messages, that the Orchestration Engine understands. Each interworking module provides connectivity to a single application or network entity, through its native protocol. For example, IM-ASF-SIP is used to communicate with a SIP application server through SIP. You deploy modules as you need, depending on the solution and use cases that you need to implement.

There are two types of interworking modules:

  • Network-facing modules, that connect Service Controller to session control entities, such as Mobile Switching Centers (MSCs) and Call Session Control Functions (CSCFs). Network-facing modules provide a standard, stateful frontend, and act like applications toward session control entities. Session control entities communicate with Service Controller in the same way they would communicate with applications. For example, IM-SCF provides a frontend that appears to MSCs as a standard Service Control Point (SCP).

  • Application-facing modules, that connect Service Controller to applications, such as IN SCPs and SIP application servers. Application-facing modules provide a standard, stateful frontend, and act like session control entities towards applications. Applications communication with Service Controller in the same way they would communicate with session control entities. For example, IM-ASF provides a frontend that appears to SIP applications as a standard CSCF.

Every module communicates on one end through a standard protocol with external session control entity or application, and on the other with the internal Orchestration Engine through the internal, proprietary, Session Abstraction Layer (SAL) protocol.

This section describes the types of modules available in Service Controller. For a detailed description of the modules, see Service Controller Modules Configuration Guide.

IM-SSF

IM-SSF is an application-facing module that enables Service Controller to connect to SCPs through an IN interface. You deploy IM-SSF to let an SCP control session in the legacy SS7-based network or IMS/LTE network. With IM-SSF, Service Controller acts like a standard Service Switching Point (SSP) towards the SCP, implementing the Service Switching Function (SSF) and generating IN triggers.

IM-SSF converts IN message to internal Service Controller messages, and the other way around. In addition to the protocol conversion functionality, IM-SSF supports:

  • Initial and full session control modes

    SCPs control sessions in the SS7-based network or IMS network in one of the following modes:

    • Initial session control mode: SCPs control sessions through session setup only. IM-SSF generates IN triggers during session setup, and let the SCP instruct how to handle the session; that is continue or disconnect the session. IM-SSF does not request the session control entity to arm additional Detection Points (DPs), and simply stops controlling the session once the session setup has been completed.

    • Full session control mode: SCPs control sessions through session setup and then continue controlling the sessions until they terminate. After the session setup is complete, the IM-SSF instructs the session control entity to arm more DPs. IM-SSF continues controlling the session until it terminates.

  • Originating and terminating BCSM

    IM-SSF fully implements the standard Basic Call State Model (BCSM) for both originating and terminating sessions.

  • Media resources

    IM-SCF supports both internal switch-based media resources (internal SRF) and external Intelligent Peripherals (IP) in the SS7 network. IM-SSF also supports MRFs in the IMS network. SCPs use media operations such as ConnectToResource(CTR) and EstablishTemporaryConnection(ETC) to play announcements and for user interactions.

  • GGSN Data triggers

    IM-SSF fully supports GPRS control operations.

  • Originating-side SMS triggers

    IM-SSF fully supports originating side SMS control operations.

  • Configurative IN message and IN parameters tunnelling

    IM-SSF supports tunneling of IN information. In this mode the IN-SSF encodes IN messages and parameters using XML Encoding Rules (XER) or Binary Encoding Rules (BER), and delivers the encoded message to the IM-SCF inside the internal Service Controller SAL message.

  • Switch-based charging timers and CDRs

    IM-SSF implements all SSF charging related timers. This capability enables an SCP to instruct IM-SSF to monitor call duration for online charging services, including prepaid services, and to insert charging information generated by IM-SSF into CDRs.

    You can configure the IM-SSF to perform the charging procedures. For example, to monitor call duration. Alternatively, IM-SSF can be coupled with the IM-SCF. In this case, IM-SSF instructs the IM-SCF to perform charging procedures.

  • SCP management procedures

    IM-SSF supports operations such as ActivityTest, which allows SCPs to manage the availability of services to the network.

IM-SSF is available for a variety of protocols and protocol variants, including INAP, AIN, CAP and WIN.

IM-SCF (Reverse IM-SSF)

IM-SCF is a network-facing module that enables Service Controller to connect to Service Switching Points (SSPs) and Intelligent Peripherals (IPs) through an IN interface. You deploy IM-SCF to let applications control and initiate sessions in the legacy SS7-based network. With IM-SCF, Service Controller acts like a standard SCP towards the SSP, implementing the standard Service Control Function (SCF).

IM-SCF converts IN messages to internal Service Controller messages, and the other way around. In addition to the protocol conversion functionality, IM-SCF supports:

  • Initial and full session control modes

    Applications control sessions in the SS7-based network in one of the following modes:

    • Initial session control mode: Applications control sessions through session setup only. When IM-SCF receives IN triggers for a session setup, Service Controller invokes applications and let them instruct how to handle the session; that is continue or disconnect the session. IM-SCF does not request the session control entity to arm additional Detection Points (DPs), and simply stops controlling the session once the session setup has been completed.

    • Full session control mode: Applications control sessions through session setup and then continue controlling sessions until they terminate. After the session setup is complete, the IM-SCF instructs the session control entity to arm more DPs. IM-SCF continues controlling the session until it terminates.

  • Originating and terminating BCSM

    IM-SCF fully implements the standard Basic Call State Model (BCSM) for both originating and terminating sessions.

  • Media resources

    IM-SCF supports both internal switch-based media resources (internal SRF) and external Intelligent Peripherals (IP). Applications can use resources in the SS7 network to play announcements and for user interactions. For example, application can collect subscriber input.

  • Configurative IN message and IN parameters tunnelling

    IM-SCF supports tunneling of IN information. In this mode, the application is "IN-aware". That is the application encodes IN messages and parameters using XML Encoding Rules (XER) or Binary Encoding Rules (BER), and delivers the encoded message to the IM-SCF inside the body of the SIP message.

  • Switch-based charging timers and CDRs

    Applications can control charging information in the session control entities, and leverage switch-based timers to implement online charging services.

  • SCP management procedures

    IM-SCF supports operations such as ActivityTest, which allows applications to manage the availability of the application services to the network.

  • Charging services

    IM-SCF can monitor session duration, generate credit reservation requests from application, and apply credit reservation responses on sessions.:

  • SIP back-to-back, SIP proxy, and SIP redirect application servers

    IM-SCF can be configured to work with SIP applications in any mode: back-to-back, proxy, or redirect

IM-SCF is available for a variety of protocols and protocols variants, including INAP, AIN, CAP and WIN.

IM-ASF

IM-ASF-SIP is an application-facing module that enables Service Controller to connect to SIP applications through a SIP interface. You deploy IM-ASF to let SIP applications access the network and control sessions in the network.

Every instance of the IM-ASF module can communicates with only one application server.

R-IM-ASF

R-IM-ASF-SIP is a network-facing module that enables Service Controller to connect Call Session Control Functions (CSCFs) through a SIP interface. You deploy R-IM-ASF when you want your solution to control sessions in the IMS/LTE network, and invoke applications for those sessions. In addition to the basic SIP mediation functionality, R-IM-ASF supports:

  • Charging service: in the absence of Diameter-based credit control application in the network, R-IM-ASF can monitor sessions, generate charging requests, analyze charging responses, and grant sessions with an approved time duration. R-IM-ASF can either monitor session duration, or delegate the monitoring to the CSCF.

  • Media resources: a map of media resources in the network that application can use to play pre-call, mid-call, and post-call announcements.

IM-PSX ETSI/ANSI MAP

IM-PSX is a network-facing module providing Service Controller a MAP interface to HLRs and VLRs. You deploy IM-PSX if you want your solution to connect an HLR or a VLR, obtain information on subscriber's status and location, and let SIP applications use this information.

With IM-PSX SIP applications can:

  • Query legacy SS7-based networks for information about subscribers, such as state, location, and the services the subscriber owns

  • Modify subscriber information in the legacy SS7-based network (in GSM networks only)

IM-PSX is available for ETSI MAP and ANSI-41.

IM-UIX-SMS

IM-UIX-SMS is a network-facing module providing Service Controller a Short Message Peer-to-Peer Protocol (SMPP) interface to Short Message Service Centers (SMSCs). You deploy IM-UIX-SMS if you want your solution to communicate with an SMSC, and allow SIP applications send short messages to, and receive short messages from, subscribers in your network.

With IM-UIX-SMS, Service Controller acts as an External Short Message Entity (ESME), using the submit_sm and deliver_sm to communicate with the SMSC.

IM-UIX-SMS supports:

  • Transmission of short messages to a single or multiple mobile subscribers

  • Reception of short messages from mobile subscribers

  • Scheduling delivery date and time of short messages

  • Datagram and store-and-forward delivery modes

  • Setting priorities for short message delivery

  • Different types short message data coding

  • Setting expiration time to short messages

  • Direction of short messages at specific services

IM-UIX-SMS is available for SMPP 3.4.

IM-UIX-USSD

IM-UIX-USSD is a network-facing module providing Service Controller an SMPP interface to SMSCs for Unstructured Supplementary Services Data (USSD) delivery. You deploy IM-UIX-USSD if you want your solution to communicate with an SMSC, to allow SIP applications send USSD commands to subscribers in your network.

IM-UIX-USSD is available for SMPP 3.4.

IM-PSX-Plugin

IM-PSX-Plugin is a network-facing module that provides Service Controller with a TCAP interface to entities in the legacy SS7-based network. You deploy IM-PSX-Plugin if you want applications in your solution to communicate with network entities through protocols and using messages, which other modules such as IM-SSF, IM-SCF, and IM-PSX do not support.

IM-PSX-Plugin is available for ETSI and ANSI protocols.

Supplementary Modules

Service Controller includes the following supplementary modules:

Supplementary modules are interchangeable modules that facilitate and complement Service Controller solutions in certain deployments. The use of supplementary modules is optional.

SM-LSS

Local Subscriber Server (LSS) is an implementation of a subscriber profile server that can be used as a source for service orchestration logic. LSS stores subscriber profiles, including the orchestration logic that the Orchestration Engine uses to orchestrate applications for the subscriber's sessions. SM-LSS is available out of the box, deployed, and ready for use.

See Service Controller Modules Configuration Guide for detailed description of the SM-LSS.

SM-PME

SM-PME can be added to the orchestration chain, as if it was another application in the chain, to modify the content of messages to fit the requirements of the next application in the chain. For example, an application may require that the Subject header contains a particular value.

SM-PME can modify the headers and body of messages. You configure how SM-PME modifies the headers and body using an XML file that defines how SM-PME transforms the headers and body.

See Service Controller Modules Configuration Guide for detailed description of SM-PME.

About Implementing SIP Applications for the NGIN Solution

When deploying the Service Controller NGIN solution you can implement SIP applications that control and deliver services to sessions running in the legacy SS7-based network. Applications can redirect or disconnect a session, modify session information, implement charging services for sessions, play announcement to parties and do much more. For detailed description of the SIP interface provided by Service Controller to control session in the GSM network, see Service Controller SIP Developer's Guide for GSM.

You can implement SIP applications on any SIP application server, such as Oracle Communications Converged Application Server (OCCAS).